Convection heat transfer and temperature analysis of oil jet lubricated spur gears

Purpose This paper aims to provide an analytic technique for determining the convection heat transfer and temperature of oil jet lubricated spur gears. Design/methodology/approach A multiphase flow model is developed to calculate the convection heat transfer coefficients on different gear faces during different contact conditions. The frictional heat is calculated and a method to distribute between the two gears is developed. A finite element model is established to calculate the temperatures in both meshing and cooling processes. Findings The convection heat transfer coefficients on different surfaces are obtained successfully. Area-related formulae are developed to calculate the heat distribution coefficients. The gear temperature reaches a maximum at the beginning of meshing, then reduces and gets minimum at pitch point, after that it increases again. The gear temperature descends rapidly to steady temperature during the short time of jet cooling process. The tendency of computational results coincides well with the experimental results. Originality/value The research presented here could be used in the design phase of the jet lubricated spur gears. The precise temperature is obtained to assess the thermal capacity of gears, from which the gear parameters and oil supply conditions could be adjusted and designed.